This research is designed to evaluate the usefulness of sinusoidal angular acceleration in the identification of vestibular disorders. The experiments involve testing of both normal humans and patients with vestibular disease, as well as normal cats and cats with experimentally-produced vestibular dysfunction. A comprehensive picture of the compensatory activity of the vestibular system after damage and an improved method for evaluating vestibular activity in general are the primary objectives. The results of the work should provide better diagnostic and prognostic information regarding human vestibular disease and basic information regarding the normal physiology of the system.